Broach assembly



Feb.` 27, 1962 S. J. KOPEC BROACH ASSEMBLY Original Filed Nov. 25, 1953 4 Sheets-Sheet 1 :Snnentor (Ittotneg Feb. 27, 1962 s. J. KoPEc 3,022,710

BROACH ASSEMBLY Original Filed Nov. 25, 1953 4 Sheets-Sheet 2 :inventor (Ittomeg Feb. 27, 1962 s. J. KoPEc 3,022,710

BROACH ASSEMBLY Original Filed Nov. 25, 1953 4 Sheets-Sheet 3 J Lr/m ZOMJFF ,//H/ 223@ S. J. KOPEC BROACH ASSEMBLY Feb. 27, 1962 4 Sheets-Sheet 4 Original Filed NOV. 25, 1953 @MKM FIG. /2

3,022,710 :BROACH ASSEMBLY Stanley J..Kepec,^597 Randolph St., Northville, Mich. Continuation of appiication Ser. No. 394,407, Nov. 25, 1953. This application Nov. 1,1956,1er. No. 619,874 6 Ciaims. .(C1..29-,95.1)

This invention relates to breaches and, more particularly, to breaches for cutting helical teeth on breach bodies for forming helical teeth on gears, ammunition rotating bands, and the like. I

This is an improvement on the invention disclosed in my Patent No. 2,629,294, issued'February 24, 1953, and is a continuation of patent application, Serial'No. 394,407, filed November 25, 1953, new abandoned.

In the said parent application, an improved breach is ,disclosed wherein the cutting teeth of the breach have cutting surfaces on both the tips and the flanks thereof. This distinguishes over breaches which have been known heretofore in'that prior breaches usually had cutting edges on the tips only of theteeth.

For certain applications, it isnecessary to have ja guiding `means between the various breach ring stages :to insure that the blanks are guided through the breach in a true helical path orin a-strai'ght path. This is accomplished by providing noncutting pilot rings between Vthe stages. Also, in this combination, there maybe a plurality of conventional teeth on rings rough cutting the teeth en the blank with a ring 'having finish cutting surfaces on both ank and tip thereof 'being shaped to conform to the shape ofthe tooth'being formed.

It is, accordingly, an object of this invention to overcome defects in'priorbreaching devices and, more particularly, it is an object ofthis invention te provide a nevel breach for cutting helical teeth which is simple inconstruction, economical in cest, economical in manufacture, and eicient in operation.

Another object ofthe invention is'to provide a breach for cutting helical teeth or spur gear teeth whereby one section thereof -rough cuts the teeth and the latter ksections thereof finishthe teeth.

Still another object or the invention is to providemeans for guiding a blank through a breach Yby providing a noncutting pilot stage between various stages of the breach.

A further object of this invention is to provide a ring breach for cutting-helical teeth or spur gear teeth which has non-cutting pilot stages with plain helical teeth between various stages of the breach rings.

A still further object of the invention is to provide a novel type of breach wherein alternate stages are cut from the roots of the teeth and other alternate stages 'will cut from the sides and anks of the teeth.

-`Y et another object of this invention is Vto lprovide a ring'breach wherein a series of stages thereof will cut Vmaterial from the root of the teethandgearblank andthe next stages will cut material ifrern'the sides of the teeth.

Yet a further object of the invention is to provide a ring breach wherein the various stages of the'broach will cut progressively on the sides and'root of the tooth and helical spline pilot ring is disposed on the breach ring assembly after-the final cutting-stages'n order to assist in guidingthe shell or gear through the final stage.

it `is still another object offthis invention to provide a .ring breach for cuttingfhelical teeth'en `a blank wherein a driver travelling in a helical path is provided fer/pushing the blank through the ring breach. l

It is. still a further object of this Ainvention to'provide a ringY breach `which is adaptable for use in either a horizontaler a vertical position and wherein the breach may bepushed over `the blank or the blank may be pushed through the'broach.

With the above and other `objects in'view, the present invention consists ofthe combination and arrangement of partshereinaftermore fully described, illustrated inthe vaccompanying drawings and more particularly pointed out in the appended claims, it lbeingunderstood thatl changes may be made in the form, size, proportions, and minor details of construction without departing from the spirit or -sacrificing any of the advantages of the invention.

In'the drawings:

FIG. 1 shows a ring breach accordingte the invention wherein a pilot-ring is shown in combination with a plurality of rough cutting stages and one finishing stage;

FiG. 2 shows aplurality'of intermediate cutting stages lforthe ring breach having pilot rings disposed between alternate stages;

vFlG. 3 shows -a plurality of intermediate breach ring stages having a plain non-cutting pilot ring disposed between cutting stages wherein the teeth on the pilot ring are of the same shape -as the teeth on the cutting stage lpreceding it;

"-FiG. '4'Yshows a section of a 4ring breach wherein the sections of rings shown vrough cuton' the root of the tooth only;

1FlG.-15 shows a 'section of :airing breach wherein the rings shown rough cut en the sidesef the tooth only;

FIG. 6 shows asection of aring breach wherein several rings of teeth of the section ofthe rings shown finish cut on the sides of thetoeth of the gear blank;

FIG. 7 shows several stages .of the rings of a ring breach wherein the cutting states finish Vcut on thereots of the teeth-ofthe gear blank only;

FIG. 8 shows the final stage of a ring breach wherein the tinal stages finish cut en the sides of the teeth only;

FIG. 9.ashews a section of the final stages ofthe ring `broachwherein the .teeth of therings finish cuton the root of the tooth only;

FIG. l0 shows theiinal stages of a ring'broach wherein `theieeth of the rings finish cuton bothsides and roots :of the teethofethegear blank;

FIG. 1.1.1 .showsfa clamping type ofdriver forluse in ,connection with a ring'broach; and

FIG. 212 is a plan view of the-breach assembly.

Referring more specifically to the drawings, FIG. `1 shows a cup shaped holding member 1 having an axially vextending aperture V2. The aperture 2 is tapered at 3 and counterbored at 4. Annular breach rings 5, 5a, 5b, 5c, 5d, and e are dispesedinthe counterbore e in axial alignment therewith.

Thev rings 5, 5a, 5b, Sc, -and V5d lhave longitudinally yextending Vgrooves 7 and 8 for engaging keys 9 in :the Vcounterbore 4. The `breach rings 5, 551,5!7, 5c,fand 5d .havefhelical shaped cutting teeth 11, lla, 1lb, llc, and flflld, f-respectively,rfor hogging off er rough cutting the major portion ef the :material to -be removedirem betweenthe'sides -androots of the teeth of a -gear .blank erionftherotating bandof a projectile passingthroug'n the breach. Teeth 152 on the breach ring 6 are of a predetermined size and diameter te cut the nished tooth profile required on the teeth of the blank orrotating band `of the projectile. `Each ring 5,501, "5b, 5c, Sd, and 6'has annular semicircular shaped intermediate grooves lz14, 14a,ib, 14C, 14d, and y15 at the top side thereof and -each ring 5, 5a, 5b, 5c,-5d, and f6 has an inner marginal .groove 16,:1,6a,1`16b,.16c, 16d, i7, 17a, 17h, 217C, andi-7d formedtherein. The grooves 16,16% v,16b,6c, and A16d merge in the grooves 17, 17a, 17b, 17C, and 17d on the underside of the pilot ring and on the underside of the preceding ring thereto. The groove 17 on the broach ring 6 merges with a marginal groove 22 on the underside of the broach ring d. In like manner, on the iinish stages, the groove 22 merges with a groove 18.

A pilot ring 23 is disposed in the counterbore 4 of the holding member 1 in axial alignment with the broach rings 5, 5a, 5b, 5c, 5d, and 6. The pilot ring 23 and the broach rings are connected in the kcounterbored member 4 by means of bolts 24 whichV are threaded to receive nuts 25 which are seated in a counterbore 26 and are attached to a threaded end 27 of the bolts 24. Heads 30 of the bolts 24 are nested in counterbores 31 in the end o the counterbored member 4.

rIhe annular grooves 14, 14a, 1411, 14e, 14d, and 15 are connected with the open inner annular grooves 16, 16a, 1Gb, 16o, and 16d by passages 36, 36a, 36b, 36C, 36d, and 37 which are tangent to the outer diameter of the open grooves so that air passing from the grooves 14, 14a, 14h, 1de, 14d, and 15 to the open inner grooves will move circularly therearound to form a turbulent air stream therein and to cool the teeth of the broach rings and to cool the chips therein and move the chips in a circular path.

rlhe inner open grooves provide a depository for the chips cut from between the teeth on the blank or band. Air is passed to the grooves 14, 14a, 14h, 14C, 14d, and 15 through passages 38 connected to a suitable air source by threaded counterbores 138, l38a, 13811, 133C, 1380?, and 139. Lubricant likewise may be passed into the circular grooves 14, 14a, 14b, 14C, 14d, and 1S through passageways 39 whereby it passes to the cutting teeth of the broach rings 5, 5a, 5b, 5c, 5d, and 6 to provide lubrication for the teeth.

The axially extending width of the inner open grooves is preferably less than the width of the teeth to be formed on the workpiece in order that the workpiece will move in a true helical path without any tendency to become misaligned. The internal diameter of the pilot ring 23 is approximately the size of the diameter of the projectile so that the projectile or gear blank may be guided in a straight line through the broach assembly. The pushing member shown in FIG. l1 may be either a straight ram or it may be clamped to the gear to rotate the gear in the desired helical path.

In the embodiment of the invention shown in FIG. 2, plain pilot rings 123 and 123e are disposed between rough cutting stages 105 and 10511. The rough cutting stages 105 and 105:1 are exactly the same as the rough cutting stages 5, 5a, 5b, 5c, and 5d shown in FIG. 1; however, it has been found desirable in certain applications of tooth cutting to provide plain pilot rings between the rough cutting stages on a ring broach. The rough cutting stages 105 and 105g have cutting teeth 111 and 111e thereon and plain pilot rings 123 and 123e have inner surfaces 123a and 123b which are adapted to slidingiy engage the outer periphery of the blank as it is pushed through the broach. The broach rings are provided with grooves 116 which merge into grooves 117 exactly as the grooves in the embodiment of the invention shown in FIG. 1 and the air passages, lubricating passage, and supporting means may be the same in this embodiment of the invention as that in the embodiment shown in FIG. l. It has been found desirable in some applications to have one intermediate plain pilot ring between two roughing stages and in other applications to have an intermediate pilot ring between each alternate stage.

The embodiment of the invention shown in FIG. 3 shows broach rings 223 and 223e which are taken from a section of a broach assembly similar to the assembly shown in FIG. l. A pilot ring 225 has a smooth inside surface 250 to engage the outside of the blank and rough cuttingV teeth 205 and 2i5a are disposed around the periphery of the inside of each broach ring. A pilot ring 230 is disposed between the rings 223 and 223ml and an inside surface 231 is smooth and there is not cutting edge thereon. Teeth 232 are made in the form of a helix to follow the path cut by the stage 205 in the head thereof to guide the blank through the broach ring. These non-cutting helical teeth may be disposed between alternate cutting stages or they may be arranged between various stages or cutting rings throughout the broach as required for the individual application.

In breaches of the form shown in FIG. 1, it has been found desirable in some applications to alternate the cutting action of the stages as the work proceeds through the broach. For example, in FIG. 4, a ring broach stage is shown which is adapted to cut on the root of the tooth only; that is, thecutting surface 311 is formed on the inside of each cutting tooth while edges 312 are smooth and do no cutting. A ring portion 395 corresponds to the ring portion 23 on the broach member shown in FIG. 1.

FIG. 5 discloses a broach ring 405 which is adapted to cut on the sides of the teeth only having the cutting surfaces 411 on the edges which are adapted to engage the sides of the teeth and the tips of cutting teeth 412 are smooth and do no cutting. vThe broach rings such as the ring 395 shown in FIG. 4 and the'ring 405 shown in FIG. 5 may be alternated in a ring broach assembly; that is, a broach ring having teeth cutting on the sides of the teeth will follow a'ring having teeth cutting on the root, etc. so that one broach ring will cut on the root of a tooth and the next will cut on the side in a broach assembly' such as shown in FIG. 1. In other applications, it has been discovered that it is desirable to have a series of rings carrying cutting teeth, such as the ring 305, to cut the root of the blank teeth followed by a series of rings cutting the ank or side of the tooth in a broach assembly such as shown in FIG. 1. It is desirable in some such cases to provide a non-cutting pilot ring between various intermediate stages of broach rings.

In FIG. 6, a series of broach rings 565, 505:1, and SOSb are shown disposed with cutting edges 511, 511:1, and l511b for cutting on the side of the tooth. In FIG. 7, a series of broach cutting rings 605, 60541, dtlb, and 695C are disposed to cut in sequence on the root of the teeth of the blank only. In some applications, it is desirable to put the broach rings shown in FIG. 6 in one sequence and the broach rings shown in FIG. 7 in another sequence to follow the broach rings shown in FIG 6 to form pre-engraved bands on a rotating band of a shell or to form helical teeth or spur gear teeth on a gear blank.

FIG. 8 shows a cutting ring 70S having a cutting edge '766 for cutting on the side of the tooth only and showing a smooth surface 706a for smoothly sliding over the root. FIG. 9 shows a section of a broach ring having finished teeth 805 having cutting edge 866 for cutting on the root only. In the same application for cutting certain materials, it has been found that it is desirable to have the broach rings in the iinal finished stage perform two separate functions, one to cut on the side of the tooth to finish the ank thereof only and the following stage to finish the root thereof only. It has been found advantageous in some cases to put the root finishing stage ahead of the side finishing stage and vice versa. The section of broach ring shown in FIG. l0 shows a cutting tooth 905 of a broach ring, the tooth having a cutting edge 9416 for cutting the edge of the blank tooth and an edge 907 for cutting the root of the tooth, the tooth being disposed at 9119.

FIG. 11 shows a ring broach 9111 which is similar to the ring broach shown in FIG. 2 and which is provided with a driver 962. The gear blank or blank of whatever irregular shape on which it is desired to cut a tooth to engage the teeth is shown at 93 and is clamped by means of a clamp 904. The diameter of the clamp 964 is of slightly smaller diameter than the diameter of the pilot ring and it projects =beyond the gear blank 903 and has a counterbore 965e: which accommodates a clamping device 966:1 for removing the pilot and the blank 963 from the driver 9%2. This pilot assists in guiding the clamp 996e through the broach ring. In applications in cutting soft metals and the like, it has been discovered that no guide is necessary to rotate the blank 963 as it passes through the broach; however, in applications in cutting some kinds of metal, it has been found desirable to provide a helix guide member, such as a track 967:1, to rotate the driver as the gear progresses through the ring broach. The track 907a is adapted to engage a fixed drive member on the frame of the machine operating the driver to rotate the blank 903 in a helical path.

The broach ring setup using two or more stages and with or Iwithout a clamp type driver can be used to broach a Variety of irregular or regular shaped workpieces and, also, helical tooth gears and spur gears. The cutting action is the same in this case as described above. The driver would be either a clamp type or simple push type. The driver would have a rotating provision, such as that which is illustrated in FIG. 11 at 907a, and clamping means such as the clamp 904 to clamp the work in place in the proper location. In some applications with the above illutsrations, it will be found that it is necessary to invent the broach ring and push the workpiece upward. It is also desirable and sometimes necessary for the work to be performed in a horizontal position. When cutting soft metals and in forming teeth on small diameter pieces, it is not necessary to use the guide rings, especially when a clamp type driver is used.

The foregoing specification sets forth the invention in its preferred practical forms but it is understood that.

the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A broach assembly for cutting teeth on a generally cylindrical blank comprising two axially aligned annular broach rings having helical cutting teeth on the inner sides thereof, the teeth on one of said ring rough cutting and the teeth on the other said ring nish cutting, and

having blunt edge teeth thereon guiding means to guide a blank adapted to be machined through said broach rings, said means comprising a Abroach ring said blank through said rings in a helical path, said cutting teeth each having cutting edges on the sides and tips thereof, said cutting edges on one stage rough cutting the sides and tips of said teeth being formed and said other ring iinish cutting said sides and tips of said teeth.

2. The broach assembly recited in claim` l wherein a plurality of finish cutting teeth are provided, some of sair iinish cutting teeth having cutting edges cuttin on the root surface and other said teeth cutting on the tlank surface of blank teeth.

3. The broach assembly recited in claim l wherein a plurality of broach rings are attached together in juxtaposition and axial alignment having teeth for rough cutting a blank.

4. The broach assembly recited in claim 3 wherein a plurality of broach rings are attached together in juxtaposition having nish cutting edges thereon for iinish cutting said teeth, said nish cutting teeth being disposed on the opposite side of said blunt edge teeth fromy said rough cutting teeth.

5. A broach assembly for cutting teeth on a cylindrical blank comprising two axially aligned annular |broach rings having cutting teeth on the inner sides thereof, said cutting teeth on one said ring rough cutting and the teeth on the other said ring nish cutting said teeth, and means to guide a blank adapted to be machined through said broach rings, said means comprising a lbroach ring attached to said two broach rings and having blunt edge teeth engaging the edges of teeth cut `by one said cutting ring, said teeth on one said ring having cutting edges on both the sides and tips thereof, said cutting edges finish cutting the sides and tips of said teeth being formed.

6. The broach asembly recited in claim 5 wherein a plurality of broach rings are provided having rough cutting edges thereon, some of said rough cutting teeth cutting on the root and other said teeth cutting on the flank of said teeth.

References Cited in the file of this patent UNITED STATES PATENTS Re. 24,284 Kopec Mar. 5, 1957 2,237,959 Hansen et al. Apr. 8, 1941 2,511,298 Schinnerer June 13,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION `tent No. 3,022,710 February 27, 1962 Stanley J. Kopen:

n the above numbered pattfied that error appears i ers Patent should reed as It is hereby ce1` tion and that the said Lett 1t requiring correo arrected below.

Column 6, llnes 7 8 and 35, for "tips", each :currence, read roots d sealed thls 10th day of January 1967.

Signed an EDWARD l. BRENNER Commissioner of Patents 

